Project description:Aims: Mesenchymal stem cells (MSCs) gradually become attractive candidates for cardiac inflammation modulation, yet understanding of the mechanism remains elusive. Strikingly, recent studies indicated that exosomes secreted by MSCs might be a novel mechanism for the beneficial effect of MSCs transplantation after myocardial infarction. We therefore explored the role of MSC-derived exosomes (MSC-Exo) in the immunomodulation of macrophages after myocardial ischemia-reperfusion and its implications in cardiac injury repair. Methods and Results: Exosomes were isolated from the supernatant of MSCs using a gradient centrifugation method. Administration of MSC-Exo through intramyocardial injection after myocardial ischemia reperfusion reduced infarct size and alleviated inflammation level in heart and serum. Systemic depletion of macrophages with clodronate liposomes abolished the curative effects of MSC-Exo. MSC-Exo modified the polarization of M1 macrophages to M2 macrophages both in vivo and in vitro. miRNA-sequencing of MSC-Exo and bioinformatics analysis implicated miR-182 as a potent candidate mediator of macrophage polarization and TLR4 as a downstream target. Diminishing miR-182 in MSC-Exo partially attenuated its modulation of macrophage polarization. Likewise, knock down of TLR4 also conferred cardioprotective efficacy and reduced inflammation level in a mouse model of myocardial ischemia/reperfusion. Conclusion: Our data indicates that MSC-Exo attenuates myocardial ischemia/reperfusion injury via shuttling miR-182 that modifies the polarization state of macrophages. This study sheds new light on the application of MSC-Exo a potential therapeutic tool for myocardial ischemia/reperfusion injury.
Project description:Background: Allergic asthma is one of the chronic inflammatory diseases and is generally induced by CD4+ T helper 2 cells (Th2) in the context of persistent inhaled stimuli. Dendritic cells (DCs) are essential to mounting the Th2-mediated airway inflammation by presenting inhaled antigens to prime CD4+ T cells. Small extracellular vesicles (sEV) derived from mesenchymal stem cells (MSCs) exhibited great interest in intractable diseases. However, whether MSC-sEV play a role on DCs in airway inflammation is still unclear. Methods: We isolate MSC-sEV using anion-exchange chromatography. Mouse bone marrow-derived DCs (BMDCs) and human monocyte-derived DCs (moDCs) were used to study the effects of MSC-sEV on dendritic cell surface molecules and their cytokine release. Mice were sensitized with house dust mites (HDM) to induce airway inflammation, and treated with MSC-sEV, The effects of sEV on murine DCs were identified. Extracellular flux analysis techniques were used to study the effects of MSC-sEV on the metabolic state of dendritic cells. RNA sequencing to study altered gene expression in BMDCs after MSC-sEV treatment. Results: MSC-sEV mitigated the accumulation of Th2-associated moDCs in mouse lung in response to HDM. MSC-sEV also decreased the activation of moDCs induced in vitro including the expression of co-stimulatory molecules and cytokines secretion. Furthermore, we identified that DCs were able to take MSC-sEV in vitro and in vivo. Mechanistically, using bulk RNA-sequencing, we found that MSC-sEV played roles in the metabolic pathway of murine DCs. Using extracellular flux analysis, we found that MSC-sEV increased the requirement of oxidative phosphorylation on moDCs. Importantly, MSC-sEV displayed similar effects on human moDCs including decreased co-stimulatory molecular and cytokine production. Conclusions: MSC-sEV are able to alter the metabolic state of DCs, favoring DCs to maintain OXPHOS (oxidative phosphorylation) rather than glycolysis, thereby reducing DCs-initiated inflammatory responses and attenuating Th2 lung inflammation, suggesting MSC-sEV can be a potential clinical therapy for airway inflammation.
Project description:To study the genes and pathway involved in cigarette smoke induced lung inflammation, and treatment with hUC-MSC-EV and hUC-MSC we have employed microarray expression profiling to identify the differentially expressed genes
Project description:Chronic lung infections and presistent inflammation are a leading cause of morbidity and mortality in people with cystic fibrosis and therefore there is a need for therapies that can simultaneously eliminate infection and the hyperinflammatory lung environment in CF. Mesenchymal stromal cell-derived extracellular vesicles (MSC EVs) represent a promising solution, offering potent anti-inflammatory, immunomodulatory, and antimicrobial properties while being safe and non-toxic. This study demonstrates the efficacy of MSC EVs in a CF mouse model of acute Pseudomonas aeruginosa lung infection. MSC EVs reduced Pseudomonas burden, immune cell infiltration, and pro-inflammatory cytokine levels in the lungs.
Project description:Extracellular vesicles (EVs) derived from three different biopsies of dental pulp mesenchymal stem cells (MSC-EVs) were isolated and characterized by different omic analysis. The goal was to characterized the EVs cargo to study their implication in an animal model of chronic cardiac inflammation
Project description:Chronic Pseudomas aeruginosa infection in the lung is a common in people with cystic fibrosis (CF). Current therapies for CF fail to eliminate persistent bacterial infections, chronic inflammation, or irreversible lung damage. Our group engineered mesenchymal stromal cell (MSC)-derived extracellular vesicles (EVs) to carry the microRNA let-7b-5p as a dual anti-infective and anti-inflammatory treatment. In a preclinical CF mice model, we found that let-7b-5p-loaded MSC EVs reduced P. aeruginosa burden, immune cells and proinflammatory cytokines in the lungs. This research hypothesized two mechanisms of the observed effects in the mouse model: anti-inflammatory properties of the let-7b-5p-loaded MSC EVs and inhibition of antibiotic-resistant P. aeruginosa biofilm formation in CF airways. Primary human broncial epithelial cells (pHBECs) were exposed to P. aeruginosa and treated with differet MSC EV conditions. The results demonstrated that MSC EVs engineered to contain let-7b-5p effectively blocked the formation of P. aeruginosa biofilms on pHBECs while also reducing P. aeruginosa-induced inflammation by CF-pHBECs.
Project description:Extracellular vesicles (EVs) harvested from conditioned media of human mesenchymal stromal cells (MSCs) suppress acute inflammation in various disease models and promote regeneration of damaged tissues. Following successful treatment of an acute steroid-refractory Graft-versus-Host disease (GvHD) patient with EVs prepared from conditioned media of human bone marrow-derived MSCs, we focus on improving the MSC-EV production for the clinical application. Independent MSC-EV preparations all produced according to a standardized procedure, reveal broad immunomodulatory differences. Only a proportion of our MSC-EV products effectively modulate immune responses in a multi-donor mixed lymphocyte reaction (mdMLR) assay. To explore the relevance of such differences, we have established an optimized mouse GvHD model. The functional testing of selected MSC-EV preparations demonstrate that MSC-EV preparations revealing immunomodulatory capabilities in the mdMLR assay also effectively suppress GvHD symptoms in this model. In contrast, MSC-EV preparations, lacking such in vitro activities, also fail to modulate GvHD symptoms in vivo. Searching for differences of the active and inactive MSC-EV preparations, we failed to identify concrete proteins or miRNAs that could serve as surrogate markers. Thus, standardized MSC-EV production strategies may not be sufficient to warrant manufacturing of MSC-EV products with reproducible qualities. Consequently, given this functional heterogeneity, every individual MSC-EV preparation considered for the clinical application should be evaluated for its therapeutic potency prior to administration to patients. Here, we qualified the mdMLR assay for such analyses.
Project description:Heterotopic ossification (HO), usually following traumatic challenges, is initiated by the aberrant osteochondral differentiation of mesenchymal stem cell (MSC). However, the role of trauma-induced inflammatory exposure in MSC fate determination remains unclear. Here, we found that quiescent MSC transited into cycling MSC and later gave rise to chondrogenic (cMSC) and/or osteogenic (oMSC) commitment following either muscle or tendon injury via single-cell RNA sequencing and lineage tracing analysis. Further spatial transcriptome analysis revealed that cycling MSC, cMSC and oMSC resided in the inflammatory niche comprised of monocytes/macrophages, neutrophils, dendritic cells (DCs), NK cells, T and B lymphocytes. We uncovered the diversity of each type of immune cells during MSC development and demonstrated that macrophages, including M1 and M2 subtypes, dynamically promotes proliferation and osteochondral differentiation of MSCs. Additionally, neutrophils and NK cells are essential for cycling MSC transition from quiescent MSC. CD4+ and CD8+ T lymphocytes promotes chondrogenesis. CellchatDB analysis and regulon analysis identify several gene networks, which could be essential for aberrant MSC proliferation and osteochondral differentiation respectively. Collectively, our findings indicate that inflammation is necessary to regulate MSC fate and uncovered the molecular landscape of osteoimmunological interactions that occur during aberrant osteochondral differentiation that could be useful for HO treatment.
Project description:Heterotopic ossification (HO), usually following traumatic challenges, is initiated by the aberrant osteochondral differentiation of mesenchymal stem cell (MSC). However, the role of trauma-induced inflammatory exposure in MSC fate determination remains unclear. Here, we found that quiescent MSC transited into cycling MSC and later gave rise to chondrogenic (cMSC) and/or osteogenic (oMSC) commitment following either muscle or tendon injury via single-cell RNA sequencing and lineage tracing analysis. Further spatial transcriptome analysis revealed that cycling MSC, cMSC and oMSC resided in the inflammatory niche comprised of monocytes/macrophages, neutrophils, dendritic cells (DCs), NK cells, T and B lymphocytes. We uncovered the diversity of each type of immune cells during MSC development and demonstrated that macrophages, including M1 and M2 subtypes, dynamically promotes proliferation and osteochondral differentiation of MSCs. Additionally, neutrophils and NK cells are essential for cycling MSC transition from quiescent MSC. CD4+ and CD8+ T lymphocytes promotes chondrogenesis. CellchatDB analysis and regulon analysis identify several gene networks, which could be essential for aberrant MSC proliferation and osteochondral differentiation respectively. Collectively, our findings indicate that inflammation is necessary to regulate MSC fate and uncovered the molecular landscape of osteoimmunological interactions that occur during aberrant osteochondral differentiation that could be useful for HO treatment.
Project description:Although the master transcription factors (TFs) are the key to the development of specific T cell subsets, whether additional transcriptional regulators are induced by the same stimuli that dominantly repress development of other T cell lineages has not been fully elucidated. Using Transforming growth factor-b (TGF-b) induced regulatory T cell (iTreg) system, we identify the TF Musculin (MSC) as critical for iTreg development by repression of TH2 transcriptional program. Loss of MSC reduces Foxp3 expression and induces TH2 differentiation even under TGF-b induced iTreg differentiation conditions. MSC mediates this effect by interrupting binding of GATA3 to TH2 locus and reducing intrachromosomal interactions within the Th2 locus. MSC-deficient iTregs are not able to suppress TH2 responses and the Msc–/– mice spontaneously develop gut and lung inflammation with age. Our data indicate that MSC enforces Foxp3 expression and promotes unidirectional induction of iTregs by repressing development of the TH2 developmental program.